This is a tricky error. I still had the svn checkout of the previous version on my disk: /gnu/store/4a6ck86ap94m397vmycxy98bmhws7h6a-svn-checkout So the recipe worked for me, since the hash and the file name corresponded to the package recipe. However, instead of the new, I actually compiled the old version and stored it under the new name in the store. And also hydra compiled it without complaining.
I have corrected the problem for netpbm. However, I think we should move to more descriptive directory names, where "svn-checkout" should be replaced by (string-append name "-" version) as usual. Andreas
